deploying smb?

[ScubaScotty561]

At about 60-70 feet, when deploying a smb how much air would you put into a 6ft one? Like a full breath half a breath or use the octo or what?

[DevonDiver]

It's an Open Water Diver level question.

How many atmosphere's are you at?... and how much will that air expand upon ascent?

The fraction of air expansion will indicate how much air you need to put in the DSMB relative to its volume.

[dmoore19]

It's an Open Water Diver level question.

How many atmosphere's are you at?... and how much will that air expand upon ascent?

The fraction of air expansion will indicate how much air you need to put in the DSMB relative to its volume.

Now that's helpful. With that answer one can conclude that at 33' you would put in 3' worth.

[evad]

....................

[Dsix36]

Now that's helpful. With that answer one can conclude that at 33' you would put in 3' worth.

I guess the simple open water stuff was too much for ya???

At 2 atmosphere (33 foot) it will need to be 1/2 full to be full at the surface

At 3 atmosphere (66 foot) it will need to be 1/3 full to be full at the surface

At 4 atmosphere (99 foot) it will need to be 1/4 full to be full at the surface

At 5 atmosphere (132 foot) it will need to be 1/5 full to be full at the surface

etc. etc. etc.

[Hashime]

Just a note, at 60 to 70' messing up would be bad news. As I learned during a training dive, make sure you have the smb clipped on the correct item (ie not you)

[Insta-Gator]

I guess the simple open water stuff was too much for ya???

At 2 atmosphere (33 foot) it will need to be 1/2 full to be full at the surface

At 3 atmosphere (66 foot) it will need to be 1/3 full to be full at the surface

At 4 atmosphere (99 foot) it will need to be 1/4 full to be full at the surface

At 5 atmosphere (132 foot) it will need to be 1/5 full to be full at the surface

etc. etc. etc.

NO, he got it. His original post said it was a 6' smb. His confirmation reply said 3'. In my book 3' is half of 6'. Don't be so anxious to jump.

[dmoore19]

I guess the simple open water stuff was too much for ya???

At 2 atmosphere (33 foot) it will need to be 1/2 full to be full at the surface

At 3 atmosphere (66 foot) it will need to be 1/3 full to be full at the surface

At 4 atmosphere (99 foot) it will need to be 1/4 full to be full at the surface

At 5 atmosphere (132 foot) it will need to be 1/5 full to be full at the surface

etc. etc. etc.

No, I think I got it right. 3' worth in a 6' smb @ 33' sounds about right to me. Would you like me to explain the math to you?

[Dsix36]

No, I think I got it right. 3' worth in a 6' smb @ 33' sounds about right to me. Would you like me to explain the math to you?

OK, I apoligize. I missed the 6' part and thought that you were just being a smartarse.

[dumpsterDiver]

I full breath should be enough to make it partially inflated at the surface, it is not really necessary to have it fully inflated at the surface.

You do want to have enough lead on your belt so that at the safety/deco stops, you are pulling down with 3-4 lbs of force, which will be about what you need to "keep it up" (unless it is really blowing).

Also, if you are just learning to deploy an SMB from considerable depth, the less air you put in it, the less likely you are to mess up and get drug to the surface.